Many gas turbine engines, having high rotational speeds, use labyrinth seals due to their low cost, low friction and long life. A labyrinth seal (or “knife edge” seal) is a type of mechanical seal that, rather than relying on a direct contact seal, instead provides a tortuous path to help prevent leakage. U.S. Pat. No. 6,330,790 to Arora et al. describes a labyrinth seal between a bearing compartment and a compressor compartment.
It is also noteworthy that, in some systems, the labyrinth seal may be buffered with compressed air. In particular, higher pressure air from one part of the gas turbine engine or other source is used. The tapped air is ducted and provided for its pressure, and used as “buffer” air in an area of lower pressure.
The present disclosure is directed toward overcoming one or more of the problems associated with the systems discussed above as well as additional problems discovered by the inventor.